Why Smartest

Smartest introduces pytest-style fixtures for Ruby.

It is a small Ruby test runner that brings pytest-style fixture injection, explicit fixture dependencies, and fixture teardown to Ruby tests.

It is designed around three ideas:

• Tests should read naturally at the top level.
• Fixture usage should be explicit in the test signature.
• Teardown should be written only for fixtures that actually need it.

# smartest/fixtures/web_fixture.rb
class WebFixture < Smartest::Fixture
  fixture :server do
    server = TestServer.start
    on_teardown { server.stop }
    server
  end

  fixture :client do |server:|
    Client.new(base_url: server.url)
  end
end

# smartest/test_helper.rb
around_suite do |suite|
  use_fixture WebFixture
  suite.run
end

# smartest/web_test.rb
test("GET /health") do |client:|
  response = client.get("/health")

  expect(response.status).to eq(200)
end

What to Read First

• Getting Started shows the smallest runnable test file.
• Writing Tests explains test structure and expectations.
• Skipping Tests covers skipped tests and expected failures.
• Running Tests covers autorun and the CLI.
• Fixtures explains class-based fixtures, dependencies, and teardown.
• Stubs shows fixture-scoped method stubs, plus optional autouse-style hook setup.
• Helpers explains registering helper modules from around_test.
• Why Smartest browser tests explains why pytest-style fixtures change Ruby browser testing, and walks through the Playwright-powered scaffold.
• Test a Rails app locally shows the generated same-process Rails server fixture.

Current Scope

Smartest currently focuses on a small runner API:

• top-level test
• class-based fixtures
• keyword-argument fixture injection
• fixture dependencies through keyword arguments
• fixture teardown
• suite-scoped fixtures through suite_fixture
• fixture-scoped method stubs, optional hook-scoped broad setup, and block-scoped constant stubs
• suite hooks through around_suite
• test hooks through around_test
• skipped and pending tests through skip and pending
• expectation matchers through expect
• console reporting
• a CLI runner

Nested describe blocks, watch mode, parallel execution, and file-scoped fixtures are not part of the current MVP.